The present invention relates generally to whistles, and more particularly to structures that can be mounted on vehicles to emit sound audible to nearby animals.
Various devices have been proposed for providing sound to alert animals of an approaching vehicle. U.S. Pat. No. 6,056,411, for example, describes a realignment device for a vehicle side mirror that, in one embodiment, forms a whistle designed to emit sounds at wavelengths audible to animals. Other examples are described in U.S. Pat. Nos. 4,150,637; 4,437,428; 4,903,630; 5,418,518; and 5,969,593.
It would be advantageous to have improved techniques for whistles on vehicles that emit sound audible to nearby animals.